I think this game has some real potential, but in its current state I don't think it's worth backing. I think that the most deciding factor for me at least will be efficiency. I am waiting for the day that someone creates a voxel game with near infinitie sized worlds that has a super efficient way of generating "chunks" (they don't even need to use the concept of chunks) that makes the game run really fast. To me, that's the largest downside to Minecraft and something that could really be improved upon.